<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>404 - 页面未找到</title>
    <style>
        /* 基础样式重置 */
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }

        body {
            background-color: #f8fafc;
            color: #334155;
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 20px;
            text-align: center;
        }

        /* 404容器 */
        .error-container {
            max-width: 800px;
            width: 100%;
            padding: 40px 20px;
        }

        /* 错误数字样式 */
        .error-number {
            font-size: 120px;
            font-weight: 800;
            background: linear-gradient(135deg, #3b82f6, #1e40af);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            margin-bottom: 20px;
            position: relative;
            display: inline-block;
        }

        .error-number::after {
            content: '';
            position: absolute;
            bottom: 10px;
            left: 10%;
            width: 80%;
            height: 15px;
            background-color: rgba(59, 130, 246, 0.1);
            border-radius: 50%;
            z-index: -1;
        }

        /* 标题和描述 */
        .error-title {
            font-size: 28px;
            font-weight: 600;
            color: #1e293b;
            margin-bottom: 15px;
        }

        .error-desc {
            font-size: 16px;
            color: #64748b;
            max-width: 500px;
            margin: 0 auto 30px;
            line-height: 1.6;
        }

        /* 插图容器 */
        .error-image {
            max-width: 300px;
            margin: 0 auto 40px;
            opacity: 0.9;
        }

        .error-image img {
            width: 100%;
            height: auto;
            animation: float 6s ease-in-out infinite;
        }

        /* 导航按钮 */
        .action-buttons {
            display: flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 15px;
            margin-top: 20px;
        }

        .btn {
            padding: 12px 24px;
            border-radius: 8px;
            font-size: 16px;
            font-weight: 500;
            text-decoration: none;
            transition: all 0.3s ease;
            border: none;
            cursor: pointer;
        }

        .btn-primary {
            background-color: #3b82f6;
            color: white;
        }

        .btn-primary:hover {
            background-color: #2563eb;
            transform: translateY(-2px);
            box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
        }

        .btn-secondary {
            background-color: white;
            color: #3b82f6;
            border: 1px solid #dbeafe;
        }

        .btn-secondary:hover {
            background-color: #f1f5f9;
            transform: translateY(-2px);
        }

        /* 页脚 */
        .footer {
            margin-top: 60px;
            font-size: 14px;
            color: #94a3b8;
        }

        /* 动画效果 */
        @keyframes float {
            0% { transform: translateY(0px); }
            50% { transform: translateY(-15px); }
            100% { transform: translateY(0px); }
        }

        /* 响应式适配 */
        @media (max-width: 600px) {
            .error-number {
                font-size: 90px;
            }

            .error-title {
                font-size: 24px;
            }

            .error-image {
                max-width: 220px;
            }

            .btn {
                width: 100%;
                max-width: 220px;
            }
        }
    </style>
</head>
<body>
    <div class="error-container">
        <!-- 错误数字 -->
        <div class="error-number">404</div>
        
        <!-- 错误标题 -->
        <h1 class="error-title">页面未找到</h1>
        
        <!-- 错误描述 -->
        <p class="error-desc">
            抱歉，您访问的页面不存在、已被删除或暂时不可用。<br>
            请检查您输入的网址是否正确，或尝试其他页面。
        </p>
        
        <!-- 插图 -->
        <div class="error-image">
            <img src="https://picsum.photos/seed/error404/600/400" alt="页面未找到插图">
        </div>
        
        <!-- 操作按钮 -->
        <div class="action-buttons">
            <a href="/" class="btn btn-primary">返回首页</a>
            <a href="javascript:history.back()" class="btn btn-secondary">返回上一页</a>
        </div>
    </div>
    
    <!-- 页脚 -->
    <div class="footer">
        © 2024 网站名称 - 如有问题请联系客服
    </div>

    <script>
        // 简单的交互效果
        document.addEventListener('DOMContentLoaded', function() {
            // 为返回上一页按钮添加禁用状态检测
            const backBtn = document.querySelector('.btn-secondary');
            if (!history.length || history.length <= 1) {
                backBtn.style.opacity = '0.7';
                backBtn.style.cursor = 'not-allowed';
                backBtn.addEventListener('click', function(e) {
                    e.preventDefault();
                    alert('无法返回上一页');
                });
            }

            // 添加页面载入动画
            const container = document.querySelector('.error-container');
            container.style.opacity = '0';
            container.style.transform = 'translateY(20px)';
            container.style.transition = 'opacity 0.6s ease, transform 0.6s ease';
            
            setTimeout(() => {
                container.style.opacity = '1';
                container.style.transform = 'translateY(0)';
            }, 100);
        });
    </script>
</body>
</html>